Apparatus for delivering a mixture of gas and air.



G. KEITH.

APPARATUSFOR DELIVERING A MIXTURE OF GAS AND AIR. APPLICATION FILED MAY 24. i917.

1,250,319; Patented Dec. 917.

APPARATUS FOR DELIVERING A MIXTURE 0F GAS AND AIR.

APPLICATION FILED MAY 24; I9I7.

Patented vDee. 18 1917.

" 0 y I a k 7' Z @l mumum n Ir J 6 Enroll.

GEORGE KEITH, OF LONDON, ENGLAND, ASSIGNOR F ONE-HALF TOJ'AMES KEITH, OF LONDON, ENGLAND.

APPARATUS roa nanrvnnme A Mrxronn or GAS AND AIR.

Original application filed September 19, 1916, Serial No. 121,030. Divided and thi a licati 1917. Serial No. 170,789. E g i To all whom it may concern:

Be it known that I, GEORGE KEITH, a subject of the King of the United Kingdom of Great Britain and Ireland, and residing at London, England,-have invented a certain new and useful" Improvement in Apparatus for Delivering a Mixture of Gas and Air or Oxygen for Combustion, of which the following is a specification.

This invention relates to'an improved apparatus for delivering a mixture of gas and air (or oxygen) for combustion, for .example, in a gas-fired furnace, oven or other installation, and it has for its primary object to render practicable the maintenance ofthe correct proportions of gas .and air (or oxygen) irrespective of variations in the quantity of the mixture being dealt with.

In the specification of the co-pending application Serial No. 121030, of which the present application is a division, is described the method for which the apparatus is employed, the said method consistin in injectmg one of the constituents of t e mixture and inducin the flow of the other constituent, while governing the pressure of the induced constituent to maintain the ressure proportionate to the resistance 0 ered to the flow of the mixture, whereby variation in the resistance of the nozzle, of the furnace or the like being fired, or of the flue, may be automatically. compensated for it being understood that variation in the quality of the mixture must otherwise result from variation in the resistance to be overcome.

As pointed out in the specification of copending application Serial No. 121030, yariation of the resistance ma be due to variable heating up of the mlxture before it issues from the nozzle,-fluctuation of the temperature in the furnace or the like and consequent variation in 'the contraction or the products of combustion, introduction or withdrawal of materials being heated,-.op'en- I ing or closing of doors or of dampers, va-

{riations of pressure in the flue, or to other causes; by the present invention the effect on the quality of the mixture of all such p ssible causes of variation .maybe g m. -matically compensated for.

The preferred form of governing devioe employed c mprises a, diaphragm casing in Specification of Letters Patent.

Patented Dec. 18,1917. May 24,

that the gas is previously brought to a pressure equal to that prevailing at the final outlet for the products of combustion, e. g., to atmospheric pressure, if the final discharge be directly into the atmospherefor to the pressure prevailing in the chimney.

' In case the gas pressure is to be maintained at atmospheric pressure," the back of the diaphragmmay' be left open; if the gas is to be brought to a pressure equal to that prevailing in the chimney, the connection from the back of the diaphragm may be led to the chimney. I

The invention is illustrated by way of example in the accompanying drawings in which Figure 1 is a vertical section showing the diaphragm casing and injector. with a connection from the back of the diaphragm to a point on the delivery side of the injector. Figs. 2, 3 and 4 represent diagrammatically three forms of connection. Fig. 5

.is a vertical section through the diaphragm oxygen where the induced medium is air or oxygen and the injected medium is gas.

Referring to the drawings, 1 denotes the diaphragm casing inwhich is fitteda thin membrane 2' whi :h is preferably disposed in'a vertical plane to eliminate the efiect of weigltit and-isoperatively connected with aed to govern the. pressure of gasvalve 3,. preferably constituted as a balancedbutterfly valve of substantially elliptical form-adapted" to be seated on theme;

c of air to the injector.

chined internal surface of a cylindrical valve casing a in communication with the gas inlet 5it being understood, however,

that any suitable form of valve, balanced or .5 otherwise, may be provided.

The valve 3 is so mounted as to be immovable laterally though not liable to be jammed with grit or the like, being carried by a hinge pin passing through lugs on a a bracket member 6 fitted within the casing 4..

The membrane 2 is operatively connected with the valve 3 by a closely wound helical spring 7 one end of which is connected to the membrane 2 and the other end of which is connected to the valve-operating lever 8,

the spring being of sufiicient strength to insure that the valve 3 shall be properly closed when the spring 7 is stressed but being capable of further extension in case of such acac cumulation of pressure of the gas on the membrane when the outlet of the governor is closed a's'to move the membrane against the face of the diaphragm casing-the ar rangement being such as to obviate straining of the valve.

The connection between the back of the diaphragm and the injector is represented by a tube 9 which is led to the expansion tube 10 of the Venturi tube and which may tergn minate flush with the internal wall of the Venturi tube with its mouth facing, across stream, as in Figs. 1 and 4:, or may project into the interior thereof with its mouth facing up stream, as in Fig. 2, or down 35 stream, as in Fig. 3, or in any intermediate position, according as it'is intended to estab lish pressure above or below that of the mixture in the expansion tube having regard to the conditions of construction and operation.

Whichever of the arrangements described be adopted, increase or decrease of the resistance offered to the flow is instantaneously responded to by the governor, therconsequential alteration of the pressure of the gas dill . as supply to the injector resulting in maintenance of the uniformity of quality of the mlxture.

It is to be understood that the connection to the back of the governor diaphragm need an not be taken from the expansion tube but ,may be conveniently taken from any oint between the .inlet of the injector an the burner nozzle, or even from the furnace itself, although in the last mentioned case there will be no provision for compensation in respect of expansion before passage of the mixture through the nozzle. To, effect the initial adjustment of the pro: portions of gas and air ,or tq effect any desired variation in the adjustment, fa coclr 12' or its equivalent is fitted in the connection 11 fordelivering gas rom;th e diaphragm casing 1 to the injector.

he cock 13 serves to re income While the apparatus illustrated is particularly applicable for delivering a self-burning mixture of gas and air to gas-fired turnaces, it is to be understood that the invention is not confined to such application, but includes the delivery of gas and air (or oxygen) in given proportions to ovens, burners or other installationswhether the mixture to be consumed be self-burning or otherwise.

If air (or oxygen) be the induced medium, the governing device will, of course, be interposed in the air (or oxygen) inlet connection and will serve to govern'the pressure of the air (or oxygen) admitted, while the gas connection will be taken to the nipple of the injector.

What I claim is 1-. An apparatus for deliverin a mixture of gas and a comburent medium. or combustion, comprising, in combination, an-injector device for injecting one of the constituents of the mixture, an inlet connection for the induced constituent, and a governing device interposed in the said inlet connection and adapted to govern the pressure of the induced constituent in dependence on the resistance ofiered to the flow of the mixture, said governing device comprising a valve and a diaphragm connected with said valve, and means, controlled by'the fluid pressure resulting from the operation of said injector device, for automatically controlling the amount of the induced constituent or medium in proportion to the amount of the constituent or medium delivered by said injector device.

2. An apparatus for delivering a mixture of gas and a comburent medium for combustion, comprising, in combination, aninjector device foreinjecting one of, the constituents of the mixture, an inlet connection for the induced constituent, and a governing device interposed in the said inlet connection and adapted to govern the pressure of the induced constituent in dependence on the resistance offered to the flowof the mixture, said governin device comprising a valve and a vertica y disposed diaphragm connected with said valve, and means, controlled by the fluid pressure resulting from the operation of said injector device, for automatically controlling the amount of the induced :c'onstituent'or medium in proportion to the amount of the constituent or me-' dium delivered by said injector device.

3. An apparatus for deliverin a mixture,

of gas and a comburent medium or combustion, comprising, iii combination, an injector device for injectioh of one ofthe constituents of a combustible mixture, an inlet, connec tion for induction of the other constituent thereof, and a governing device for govern-. ingthe pressure of the induced constituent, said governing device comprising a ivoted valve in said inlet coctioma v ve-controlling device comprising a diaphragm automatically regulated in proportion to the '13 4 forming a part of the wall of said inlet confluid pressure of said mixture.

nection and providin a chamber at the In testimony whereof I have signed my outer side of said diap ragm, a spring conname to this specification in the presence 5 necting said diaphragm with said valve, and of two subscribing witnesses.

a connection forming a communication be- GEORGE KEITH. tween said chamber and the path of flowof Witnesses: the mixture; whereby the amount of the WALLACE CRANSTON Femwnarmm,

induced constituent of the mixture will be HENRY MASON. 

